GENERAL INFORMATION
The adductor pollicis is a muscle located in the palm. It plays a crucial role in the adduction and opposition movements of the thumb, enabling grasping as well as pinching actions.
ORIGIN
This muscle originates from the bases of the metacarpals of the second and third fingers as well as the adjacent capitate bone.
INSERTION POINT
The adductor pollicis inserts onto the ulnar side of the base of the proximal phalanx of the thumb.
MAJOR ARTERIES
It receives its blood supply from branches of the deep palmar arch, such as the deep palmar metacarpal arteries. These arteries provide oxygenated blood to the muscle for its proper function.
NEURAL INNERVATION
The deep branch of the ulnar nerve innervates the adductor pollicis. The ulnar nerve arises from the brachial plexus and provides motor innervation to the muscle.
TRIGGER POINT
Trigger points in this muscle may develop due to muscle tension or overuse. These trigger points can cause localised pain, tenderness, or referred pain patterns in the hand and thumb.
CONCENTRIC FUNCTION
The concentric function of this muscle involves the contraction of the muscle fibres, resulting in the adduction and opposition of the thumb. This contraction allows for movements that involve bringing the thumb toward the palm or other fingers.
ECCENTRIC FUNCTION
The eccentric function of this muscle occurs when the muscle fibres lengthen under tension. This function assists in controlled release as well as separation of the thumb from the palm or other fingers.
ISOMETRIC FUNCTION
The isometric function of the adductor pollicis involves contracting and generating tension without changing the length of the muscle. This function aids in stabilising the thumb during activities that require a static hold or resistance.
RELATED MUSCLE SCIENTIFIC NAMES
Its scientific name is also known as the adductor pollicis:
- Musculus adductor pollicis: This muscle is responsible for the adduction of the thumb, enabling it to move towards the palm and fingers, essential for grasping and pinching actions.
ANTAGONIST MUSCLES
The antagonist muscles to the adductor pollicis include the abductor muscles located on the radial side of the hand. These muscles work in opposition to the adductor pollicis, allowing for coordinated movements of the thumb and hand.
COMMON INJURIES
Common injuries associated with the adductor pollicis may include:
- Tendinitis: Inflammation or irritation of the tendon of the adductor pollicis due to repetitive use or strain.
- Muscle Strain: Overexertion or sudden traumatic events can lead to strain or tears in the adductor pollicis muscle.
EXERCISES
Exercises that target and strengthen the adductor pollicis include:
- Thumb adduction exercises: Move the thumb toward the palm against resistance to strengthen the muscle.
- Pinch grip exercises: Squeeze a small object between the thumb and fingers to improve grip strength.
- Grasp and release exercises: Practice grasping and releasing objects to enhance thumb control as well as strength.
STRETCHES
Stretching the adductor pollicis can help improve flexibility and prevent stiffness. Some stretches that target this muscle include:
- Thumb abduction stretch: Gently pull the thumb away from the palm with the opposite hand.
- Thumb extension stretch: Extend the thumb backwards and hold the position to stretch the muscle.
- Thumb opposition stretch: Touch the thumb to the base of the little finger and hold to enhance flexibility.
